src/render/font.c

#include "render/font.h"
 
/* Public-domain 8x8 glyphs, ASCII 32..126. Row-major, LSB is the left pixel. */
static const unsigned char font8x8[95][8] = {
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00}, /* space */
    {0x18,0x3C,0x3C,0x18,0x18,0x00,0x18,0x00},
    {0x36,0x36,0x00,0x00,0x00,0x00,0x00,0x00},
    {0x36,0x36,0x7F,0x36,0x7F,0x36,0x36,0x00},
    {0x0C,0x3E,0x03,0x1E,0x30,0x1F,0x0C,0x00},
    {0x00,0x63,0x33,0x18,0x0C,0x66,0x63,0x00},
    {0x1C,0x36,0x1C,0x6E,0x3B,0x33,0x6E,0x00},
    {0x06,0x06,0x03,0x00,0x00,0x00,0x00,0x00},
    {0x18,0x0C,0x06,0x06,0x06,0x0C,0x18,0x00},
    {0x06,0x0C,0x18,0x18,0x18,0x0C,0x06,0x00},
    {0x00,0x66,0x3C,0xFF,0x3C,0x66,0x00,0x00},
    {0x00,0x0C,0x0C,0x3F,0x0C,0x0C,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x0C,0x0C,0x06},
    {0x00,0x00,0x00,0x3F,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x0C,0x0C,0x00},
    {0x60,0x30,0x18,0x0C,0x06,0x03,0x01,0x00},
    {0x3E,0x63,0x73,0x7B,0x6F,0x67,0x3E,0x00},
    {0x0C,0x0E,0x0C,0x0C,0x0C,0x0C,0x3F,0x00},
    {0x1E,0x33,0x30,0x1C,0x06,0x33,0x3F,0x00},
    {0x1E,0x33,0x30,0x1C,0x30,0x33,0x1E,0x00},
    {0x38,0x3C,0x36,0x33,0x7F,0x30,0x78,0x00},
    {0x3F,0x03,0x1F,0x30,0x30,0x33,0x1E,0x00},
    {0x1C,0x06,0x03,0x1F,0x33,0x33,0x1E,0x00},
    {0x3F,0x33,0x30,0x18,0x0C,0x0C,0x0C,0x00},
    {0x1E,0x33,0x33,0x1E,0x33,0x33,0x1E,0x00},
    {0x1E,0x33,0x33,0x3E,0x30,0x18,0x0E,0x00},
    {0x00,0x0C,0x0C,0x00,0x00,0x0C,0x0C,0x00},
    {0x00,0x0C,0x0C,0x00,0x00,0x0C,0x0C,0x06},
    {0x18,0x0C,0x06,0x03,0x06,0x0C,0x18,0x00},
    {0x00,0x00,0x3F,0x00,0x00,0x3F,0x00,0x00},
    {0x06,0x0C,0x18,0x30,0x18,0x0C,0x06,0x00},
    {0x1E,0x33,0x30,0x18,0x0C,0x00,0x0C,0x00},
    {0x3E,0x63,0x7B,0x7B,0x7B,0x03,0x1E,0x00},
    {0x0C,0x1E,0x33,0x33,0x3F,0x33,0x33,0x00},
    {0x3F,0x66,0x66,0x3E,0x66,0x66,0x3F,0x00},
    {0x3C,0x66,0x03,0x03,0x03,0x66,0x3C,0x00},
    {0x1F,0x36,0x66,0x66,0x66,0x36,0x1F,0x00},
    {0x7F,0x46,0x16,0x1E,0x16,0x46,0x7F,0x00},
    {0x7F,0x46,0x16,0x1E,0x16,0x06,0x0F,0x00},
    {0x3C,0x66,0x03,0x03,0x73,0x66,0x7C,0x00},
    {0x33,0x33,0x33,0x3F,0x33,0x33,0x33,0x00},
    {0x1E,0x0C,0x0C,0x0C,0x0C,0x0C,0x1E,0x00},
    {0x78,0x30,0x30,0x30,0x33,0x33,0x1E,0x00},
    {0x67,0x66,0x36,0x1E,0x36,0x66,0x67,0x00},
    {0x0F,0x06,0x06,0x06,0x46,0x66,0x7F,0x00},
    {0x63,0x77,0x7F,0x6B,0x63,0x63,0x63,0x00},
    {0x63,0x67,0x6F,0x7B,0x73,0x63,0x63,0x00},
    {0x1C,0x36,0x63,0x63,0x63,0x36,0x1C,0x00},
    {0x3F,0x66,0x66,0x3E,0x06,0x06,0x0F,0x00},
    {0x1E,0x33,0x33,0x33,0x3B,0x1E,0x38,0x00},
    {0x3F,0x66,0x66,0x3E,0x36,0x66,0x67,0x00},
    {0x1E,0x33,0x07,0x0E,0x38,0x33,0x1E,0x00},
    {0x3F,0x2D,0x0C,0x0C,0x0C,0x0C,0x1E,0x00},
    {0x33,0x33,0x33,0x33,0x33,0x33,0x3F,0x00},
    {0x33,0x33,0x33,0x33,0x33,0x1E,0x0C,0x00},
    {0x63,0x63,0x63,0x6B,0x7F,0x77,0x63,0x00},
    {0x63,0x63,0x36,0x1C,0x1C,0x36,0x63,0x00},
    {0x33,0x33,0x33,0x1E,0x0C,0x0C,0x1E,0x00},
    {0x7F,0x63,0x31,0x18,0x4C,0x66,0x7F,0x00},
    {0x1E,0x06,0x06,0x06,0x06,0x06,0x1E,0x00},
    {0x03,0x06,0x0C,0x18,0x30,0x60,0x40,0x00},
    {0x1E,0x18,0x18,0x18,0x18,0x18,0x1E,0x00},
    {0x08,0x1C,0x36,0x63,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF},
    {0x0C,0x0C,0x18,0x00,0x00,0x00,0x00,0x00},
    {0x00,0x00,0x1E,0x30,0x3E,0x33,0x6E,0x00},
    {0x07,0x06,0x06,0x3E,0x66,0x66,0x3B,0x00},
    {0x00,0x00,0x1E,0x33,0x03,0x33,0x1E,0x00},
    {0x38,0x30,0x30,0x3e,0x33,0x33,0x6E,0x00},
    {0x00,0x00,0x1E,0x33,0x3f,0x03,0x1E,0x00},
    {0x1C,0x36,0x06,0x0f,0x06,0x06,0x0F,0x00},
    {0x00,0x00,0x6E,0x33,0x33,0x3E,0x30,0x1F},
    {0x07,0x06,0x36,0x6E,0x66,0x66,0x67,0x00},
    {0x0C,0x00,0x0E,0x0C,0x0C,0x0C,0x1E,0x00},
    {0x30,0x00,0x30,0x30,0x30,0x33,0x33,0x1E},
    {0x07,0x06,0x66,0x36,0x1E,0x36,0x67,0x00},
    {0x0E,0x0C,0x0C,0x0C,0x0C,0x0C,0x1E,0x00},
    {0x00,0x00,0x33,0x7F,0x7F,0x6B,0x63,0x00},
    {0x00,0x00,0x1F,0x33,0x33,0x33,0x33,0x00},
    {0x00,0x00,0x1E,0x33,0x33,0x33,0x1E,0x00},
    {0x00,0x00,0x3B,0x66,0x66,0x3E,0x06,0x0F},
    {0x00,0x00,0x6E,0x33,0x33,0x3E,0x30,0x78},
    {0x00,0x00,0x3B,0x6E,0x66,0x06,0x0F,0x00},
    {0x00,0x00,0x3E,0x03,0x1E,0x30,0x1F,0x00},
    {0x08,0x0C,0x3E,0x0C,0x0C,0x2C,0x18,0x00},
    {0x00,0x00,0x33,0x33,0x33,0x33,0x6E,0x00},
    {0x00,0x00,0x33,0x33,0x33,0x1E,0x0C,0x00},
    {0x00,0x00,0x63,0x6B,0x7F,0x7F,0x36,0x00},
    {0x00,0x00,0x63,0x36,0x1C,0x36,0x63,0x00},
    {0x00,0x00,0x33,0x33,0x33,0x3E,0x30,0x1F},
    {0x00,0x00,0x3F,0x19,0x0C,0x26,0x3F,0x00},
    {0x38,0x0C,0x0C,0x07,0x0C,0x0C,0x38,0x00},
    {0x18,0x18,0x18,0x00,0x18,0x18,0x18,0x00},
    {0x07,0x0C,0x0C,0x38,0x0C,0x0C,0x07,0x00},
    {0x6E,0x3B,0x00,0x00,0x00,0x00,0x00,0x00},
};
 
const unsigned char *font_glyph(unsigned char character)
{
    if (character < FONT_FIRST || character > FONT_LAST)
        character = '?';
    return font8x8[character - FONT_FIRST];
}
 
void font_draw(uint32_t *pixels, int stridePixels, int bufferWidth, int bufferHeight,
               int x, int y, const char *text, uint32_t color, int scale)
{
    if (!pixels || !text || scale < 1)
        return;
 
    int cursorX = x;
    for (const unsigned char *s = (const unsigned char *)text; *s; s++) {
        unsigned char character = *s;
        if (character == '\n') {
            cursorX = x;
            y += 8 * scale;
            continue;
        }
        if (character < 32 || character > 126)
            character = '?';
        const unsigned char *glyph = font8x8[character - 32];
        for (int row = 0; row < 8; row++) {
            unsigned char bits = glyph[row];
            for (int column = 0; column < 8; column++) {
                if (!(bits & (1u << column)))
                    continue;
                for (int deltaY = 0; deltaY < scale; deltaY++) {
                    int pixelY = y + row * scale + deltaY;
                    if (pixelY < 0 || pixelY >= bufferHeight)
                        continue;
                    for (int deltaX = 0; deltaX < scale; deltaX++) {
                        int pixelX = cursorX + column * scale + deltaX;
                        if (pixelX < 0 || pixelX >= bufferWidth)
                            continue;
                        pixels[pixelY * stridePixels + pixelX] = color;
                    }
                }
            }
        }
        cursorX += 8 * scale;
    }
}